During their campaign in Poland, the Germans kept only 23 divisions in the west to guard their frontier against the French, who had nearly five times as many divisions mobilized. The French commander in chief, General Maurice-Gustave Gamelin, proposed an advance against Germany through neutral Belgium and the Netherlands in order to have room to exercise his ponderous military machine. He was overruled, however, and French assaults on the 100-mile stretch of available front along the Franco-German frontier had barely dented the German defenses when the collapse of Poland prompted the recall of Gamelin’s advanced divisions to defensive positions in the Maginot Line. From October 1939 to March 1940, successive plans were developed for counteraction in the event of a German offensive through Belgium—all of them based on the assumption that the Germans would come across the plain north of Namur, not across the hilly and wooded Ardennes. The Germans would indeed have taken the route foreseen by the French if Hitler’s desire for an offensive in November 1939 had not been frustrated, on the one hand, by bad weather and, on the other, by the hesitations of his generals; but in March 1940 the bold suggestion of General Erich von Manstein that an offensive through the Ardennes should, in fact, be practicable for tank forces was adopted by Hitler, despite orthodox military opinion.

Meanwhile, Hitler’s immediate outlook had been changed by considerations about Scandinavia. Originally he had intended to respect Norway’s neutrality. Then rumours leaked out, prematurely, of British designs on Norway—as, in fact, Winston Churchill, first lord of the Admiralty, was arguing that mines should be laid in Norwegian waters to stop the export of Swedish iron ore from Gällivare to Germany through Norway’s rail terminus and port of Narvik. The British Cabinet, in response to Churchill, authorized at least the preparation of a plan for a landing at Narvik; and in mid-December 1939 a Norwegian politician, Vidkun Quisling, leader of a pro-Nazi party, was introduced to Hitler. On January 27, 1940, Hitler ordered plans for an invasion of Norway, for use if he could no longer respect Norway’s neutrality.

After France’s failure to interrupt the German conquest of Poland, the western powers and the Germans were so inactive with regard to land operations that journalists began to speak derisively, over the next six months, of the “phony war.” At sea, however, the period was somewhat more eventful. German U-boats sank the British aircraft carrier Courageous (September 17) and the battleship Royal Oak (October 14). The U-boats’ main warfare, however, was against merchant shipping: they sank more than 110 vessels in the first four months of the war. Both the Germans and the British, meanwhile, were engaged in extensive mine laying.

In surface warfare at sea, the British were on the whole more fortunate than the Germans. A German pocket battleship in the Atlantic, the Admiral Graf Spee sank nine ships before coming to a tragic end: having sustained and inflicted damage in an engagement with three British cruisers off the Río de la Plata on Dec. 13, 1939, she made off to Montevideo and obtained leave to spend four days there for repairs; the British mustered reinforcements for the two cruisers still capable of action after the engagement, namely the Ajax and the Achilles, and brought the Cumberland to the scene in time; but, on December 17, when the Graf Spee put to sea again, her crew scuttled her a little way out of the harbour before the fight could be resumed.

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